Power converting unit and system



y 1935- J. N. STOWELL 0 2,000,868

POWER CONVERTING UNIT AND SYSTEM Original Filed May 10, 1933 lhwentor Patented May 1, 19,35

. aooasks PATENT OFFICE POWER. CONVERTING UNIT SYSTEM Jerome Nathan Stowell, Fargo, N. Dak.

Application May 10, 1933, Serial No. 670,384 Renewed March 16, 1935 Claims. (Cl. 176-124) This invention relates to power converting units and systems and aims generally to provide an improved unit and system of this character which, in one illustrative application thereof, will 6 be capable of transforming a low potential input current to produce output current at high potential and of such character as to be capable of smoothly operating a neon-gas tube orthe like without flicker, and uniformly throughout its length for all practical purposes, and with very small drain upon the source of primary current. In a preferred embodiment exemplifying the capabilities of my improved system in this illustrative, application thereof, the system may be devised to produce a current output, at 17,500 volts, capable of thus operating a neon-gas tube seventy feet in length, while drawing a current of less than two (2) amperes from a six (6) volt storage battery.

Attempts have heretofore been made to operate neon-gas tubes or the like from low voltage sources of direct current by employing an induction coil to produce therefrom a high voltage current forilluminating the tube, but such systems have been found not entirely satisfactory for at least two reasons; first, because of the characteristic flicker obtained, and second, be-

cause of the inherent character of the current output of induction coils in general, which renders a neon-tube supplied with current thereby brilliant at one end and dimmer at the other.

The system of my invention, however, overcomes the above mentioned disadvantages of the usual induction coil systems, without the employment of complicated mechanism, and at the same time effects a considerable saving in current consumption as compared with the induction coil systems heretofore used, as hereinafter shown.

The accompanying circuit diagram is illustrative of a preferred embodimentof my improved system as applied to the operation of a neon-gas tube sign.

In this preferred embodiment of my invention a source of power I0 is indicated conventionallyand may be an ordinary six volt storage battery with positive and negative terminals as indicated.

The converter embodying my invention in this illustrative arrangement comprises a transformer, herein consisting of the primary H, the soft iron core l2 which advantageously may be of the closed type'and of laminated or other usual construction, and the secondary l3, in suitable ratio to the primary ll.

Arranged in parallel with the primary I l of the transformer is an electromagnet separate and apart therefrom, herein embodying the coil I4 and the soft iron core I5 of laminated or other suitable construction, which functions, with the contact means hereinafter described, to rapidly and repeatedly interrupt the current supplied to the parallel system comprising the coils l I and M. The contact means aforesaid may be of any suitable construction, but in the form shown comprises a stationary contact l6, which may be adjustable, and'a vibratory contact l'l, herein carried by a paramagnetic spring-arm l8 mounted rigidly or adjustably upon any suitable support I0, and positioned to be drawn away from the contact l6 by magnetic flux generated by the electromagnet I4, IS. The parallel system comprising the coils II and I4, proportioned so that in operation the major portion of the current passes through the coil I I and the minor portion through the coil I4, is arranged in series with the contact means l6, l1, and with the source of power M, as shown, and the contact means l6, I1 is bridged or arranged in parallel with a heavy non-electrolytic condenser 20. With this arrangement and proper adjustment of the proximity to the electromagnet of the contacts I6, I!

and of the tension of the spring-arm l8, the supply of current to the parallel system H and H of the converter will be rapidly and repeatedly broken and remade by the effect of energization and deenergization of the electromagnets ll, l5. In practice I find thatthis arrangement;in which I follow the novel method of drawing current from a low voltage source, dividing it into two portions flowing in parallel, employing one of said portions to energize an electromagnet, the magnetic flux of which is applied to operate means for rapidly and repeatedly interrupting the entire current drawn from the source, employing the other portion in parallel with the first to energize the primary of a transformer, and utilizing the magnetic flux developed by the current in the primary of the transformer solely for operation of the step-up transformer produces from such low potential source of current, a current output of high voltage and of an alternating character with the opposite sides of its cycle sufficiently equal toilluminate a lamp of the neon-gas tube type with uniform brilliance throughout its length so far as is readily perceivable by the eye, and without objectionable length, without perceptible flicker or noticeable inequality of illuminating, with the output potential at 17,500 volts, from a six (6) volt storage battery with a current drain thereon of less than two (2) amperes. In this installation I have employed a non-electrotlytic condenser 20 having a capacity of about 1.5 microfarads, and capable of withstanding a potential of 50 volts, a transformer having a primary winding of about 400 turns of number 18 wire (standard gauge) and a secondary winding of about 17,500 turns of number 36 wire (standard gauge) with an electromagnet I 4, I 5 having about 400 turns of number 16 wire (standard gauge), the rate of interruption of the circuit by the electromagnetic interrupter I l-l9 being adjusted, by adjustment of the contacts and tension of the spring l8, as aforesaid, to attain the desired character of current output, which, as a general rule, will be about 200 cycles or 400 interruptions per second.

In another installation for operating a shorter neon-gas tube, I have obtained equally satisfactory results with an output potential of 7,500 volts, and input from the six (6) volt storage battery, utilizing anon-electrolytic condenser of 1.5 microfarads capacity, and capable of withstanding a potential of 50 volts, with the transformer primary consisting of 350 turns of number 18 wire (standard gauge), the secondary of 7,500 turns of number 36 wire (standard gauge),

and the electromagnet coil of 350 turns of number 16 wire (standard gauge).

Outstanding advantages of my improved system and power unit are that it enables the production, from a low potential direct current source, of a high voltage alternating current of a character which is able to illuminate gaseous signs such as neon light signs with substantial uniformity and absence of flicker, thus overcoming the most noticeable disadvantages characterizing the illumination of such signs by induction coil systems. In addition I have found by the installations above noted that the current output obtained by my method is of a character which does not produce any appreciable heating of the tube itself, and thereby permits its usage under almost all sorts of weather conditions.

In the light of the foregoing disclosure it will be perceived by those skilled in the art that variout and sundry changes may be made, and various expedients resorted to, for applying the fundamentals of the power converting method and arrangement, power converting unit,method of illuminating gaseous tubes, and other phases of my invention, in various embodiments, and that the disclosed embodiment is to be construed as illustrative, and not restrictive, of my invention.

I claim as my invention:

1. The method of illuminating a lamp of the neon-gas tube-type substantially equally throughout its length, and without objectionable flicker, which comprises the steps of drawing a current from a low potential source, dividing the current into two portions, passing one of said portions through the coil of an electromagnet, utilizing the magnetic force developed by said electromagnet to rapidly and repeatedly interrupt the entire current drawn from the source with such rapidity as to avoid flicker and with such ratio of make to break that the illuminating current derived by the method has the opposit-e sides of its cycle substantially equal, and passing the other portion of the current in parallel with the first portion through the primary of a step-up transformer and utilizing the magnetic flux developed by the said other part .of said current solely for operation of said stepup transformer to produce a current of high voltage and of an alternating character with the opposite sides of its cycle sufliciently equal to illuminate said lamp substantially equally throughout its length.

2. A systemfor, producing, from a low potential source of current, a current of high voltage and of an alternating character with the opposite sides of its cycle sufliciently equal to illuminate a lamp of the neon-gas tube type substantially equally throughout its length, and further of a character to illuminate a lamp of said type without objectionable flicker, which comprises a step-up transformer, a separate electromagnet in parallel with the primary of said step-up transformer, a series circuit for connecting said parallel circuits with the low potential source ofpower, and vibrator contact means in said series circuits directly vibrated by energization and deenergization of said separate electromagnet to rapidly break and make said series circuit, said vibrator contact means being so tensioned that the speed and ratio of make to break produces the defined current output from said transformer.

. 3. A system of the character defined in claim 2,

having a large capacity non-electrolytic condenser in parallel with said contact means.

4. A converter of the class described comprisrect current source, dividing the current into two portions, passing one of said portions through a first circuit and utilizing it to produce electromagnetic flux, utilizing the electromagnetic flux to interrupt the entire current drawn from thesource to thus terminate the creation of said flux, reestablishing the said entire current when creation of said flux is terminated, passing the other portion of said divided interrupted current through a second circuit in parallel with the first circuit, utilizing the current flowing in said second circuit to produce a fluctuating magnetic flux, utilizing the fluctuating flux produced by" 

